Diesel or super diesel??

[Cupra_Bod]

Does anyone know the difference between super diesel and normal diesel??

Is it the same difference as 95 ron petrol and 99 super unleaded??

Is there more performance potential to be had by using the super stuff on a standard Cupra engine or only if it is mapped??

Thanks for any input...

 

[xs2man]

Can't say I noticed any performance benefit. I did do some testing a while back in my 530d. I ran 3 tanks of some of the most popular fuels on the market, from supermarkets as well as proper retailers like Shell, BP and Esso etc... Using the super diesel as well as the normal diesel. My testing was mostly related to fuel economy though.

Now, obviously it wasn't properly scientific or anything, as my driving would have changed from tank to tank. But none the less, there were some rather obvious differences with some fuels compared to others.

In general though, I found no increase in fuel economy between the super and normal diesel variants, except for Esso Super diesel, which, for some reason, did show me to get a couple extra mpg's. Then diesel from Asda and Tesco performing the worst, for me, during my testing.

Surprisingly, to me at least, Morrisons fuel performed just as well as Shell or BP standard diesels. Which I saw very little difference to their super diesel offerings. Sainsburys falling only marginally behind.

Now, I generally just fill up at Morrisons. It's the handiest for me almost (Asda and Shell are equally as handy for me, but Asda's worse performance, and Shell being a couple ppl more means Morrisons is usually the pick). I shop there anyway, so get the reward points, buy amazon vouchers there for their fuel save, and their fuel provides pretty much the same economy as Shell. Esso Super diesel is, unfortunately, to difficult to get for me to use regularly.

It's worth baring in mind, that this testing was completed over many thousands of miles, as it was 3 straight tanks of each fuel on the trot to compare values against.

Of course, that's with relation to diesel only, and only really for fuel consumption. When I ran my stage 2 1.8T (uprated turbo's, injectors, intercoolers, sports cat, live mapping etc...) I only ran either Momentum 99 or V-Power. But then on a car like that, with money spent on performance tuning, an extra couple quid per tank is nothing, whether the benefits are a placebo affect or not. It's not like you are worried about fuel economy when you are running a tuned petrol motor.

 

[Cupra_Bod]

Thanks for your reply, I agree with you as far as the super unleaded goes as I used it in my Astra coupe turbo and definitely noticed a difference.

As far as my Cupra TDI I use super diesel and my partner also has a Cupra TDI which she only uses normal diesel and I would say I have the edge as far as economy goes but I think that has a lot to do with my driving compared to hers...

 

[xs2man]

Like I said, different driving profiles do make the bigger difference. But I do believe that the Esso Super diesel does actually make a difference. Where I found no noticeable difference with either Shell or BP personally.

What I did notice making a difference, although it was more to do with the soot out the tailpipe, and cold starts, was a shot of 2 stroke engine oil in the tank. I don't do it on my 530d, as it's pretty new, but with my old Passat (2003 1.9 TDI 130 with 150k) it certainly ran a bit better. I used around 250ml to a full tank. Cheap as chips from Morrisons too.

Just bought my Alhambra, so haven't filled it up yet. But I do have some Redex sitting around, so I'll use that on the first couple tanks anyway, and once I'm finished my suppies, I'll see how it goes with a little 2 stroke.

 

[Cupra_Bod]

I have only used BP fuel so I cant say I have tested the other variants available yet but I just wondered if there were many differences.

That's interesting what you say about the 2 stroke oil, how many tanks do you use that in? every tank or once in a while as a treat??

 

[xs2man]

I used it every tank. You get 500ml bottles for £1.99 from Morrisons, so half a bottle per tank. So only £1 per tank, fired in before filling.

It was a tip I picked up years ago, but never really ran a diesel motor with high enough miles (low enough value) to consider trying it. Worked great though. While I still wont run it in my 2 year old BMW, my Alhambra is a '07, and will be happy to try it in that.

Might be worth doing your own research on it first though. I noticed an improvement for sure, but that's not to say everyone will. My car was on 150k afterall.

 

[Cupra_Bod]

I will do some research but I think it sounds worth a try as my cupra is a 54 plate with 130k on the clock, thanks for the info!

 

[mty12345]

I'd be SUPER cautious before you go mixing oil in with your diesel. Who knows what kind of damage that would do to seals and injectors etc etc. It's your car, your choice, but there is no way i'd even think about doing that. I can't see a single benefit myself, only drawbacks

 

[xs2man]

Obviously never tried it, or looked into it.

Like I said, do your own research first, but I had no issues. And I had run chip fat in the past too.

What do you think diesel is if not oil though? And 2 stroke oil is designed to be mixed with fuel, providing extra lubrication.

 

[xs2man]

Here is on eof the posts a quick google brings up about using 2SO in a diesel car. This was on a 320d. Unsure of the age if it was a E90 or E46 though.

Anyway, I've been reading in a few forums about the benefits of adding 2-stroke mineral oil (low ash) to your fuel tank before filling the car with diesel. I couldn't find any negatives or dangers in doing so, only positive feedback and some pretty convincing evidence.

It's important that the oil is Jaso FB spec compliant, low ash, and not fully synthetic - because this does not burn well.

This 2-stroke/diesel blend apparently brings the following benefits.

1. 2-stoke burns better and more cleanly than diesel. This means more complete combustion of your diesel fuel.

2. Helps to initially clean out the engine internals, and keeps them clean.

3. Restores missing lubricants (and more) from low sulphur diesel.

4. The engine runs much more smoothly and is much quieter.

5. Significant reduction in smoke from exhaust (due to better combustion). Applicable for cars with no DPF

6. Keeps the DPF cleaner.

7. Increases the life of the engine, including injectors, fuel pump, etc.

So, I thought I'd give this a go!

Last night, I put 300ml of 2-stroke oil, into my car, before filling up with Shell Fuelsaver Diesel. I then set of on a 125 mile journey home, not expecting much...

However, after a short while I found that the engine was quieter and running much more smoothly! Much less clatter on the outside and definitely quieter in the cabin.

The car seemed to be a little more responsive and pulled better in higher gears, especially at low rpms. I found that I didn't have to change down nearly as much when cruising at low speeds and whilst accelerating.

My car used to let out a little black smoke when I put my foot down, slightly embarrassing! However, now there seems to be none at all! At worst there is a little haze, but nothing more than that.

Based on what I've found so far, I'd definitely recommend giving this a go. I was really sceptical about noticeable results, but it seems to be working a treat!

Again, as I said though, the OP should do his own research before deciding to do it. I did it, and saw big improvements in the way it drove. For me. Have heard of it working wonders in keeping EGR's and the like clean too.